Three-dimensional modeling device

Abstract

To suppress damage and deformation of one molding layer having a first material region and a second material region when the molding layer is irradiated with a laser.SOLUTION: A three-dimensional molding apparatus 1 includes a stage 22, first material supply means 30A for supplying a first material Oa, second material supply means 30B for supplying a second material Ob, laser irradiation means 28, and a control part 23 for dividing laser irradiation scanning into first laser irradiation scanning and second laser irradiation scanning and controlling the laser irradiation means 28, in which the control part 23 irradiates a first material region R1 with a laser L by first laser irradiation scanning, and irradiates a second material region R2 with the laser L by second laser irradiation scanning, when the first material region R1 and the second material region R2 are arranged in one molding layer 500 so as to be adjacent to each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a three-dimensional modeling apparatus. [Background technology]

[0002] Conventionally, three-dimensional modeling devices that manufacture three-dimensional objects by stacking modeling layers have been used. Among these, there are three-dimensional modeling devices that stack modeling layers using multiple materials. For example, Patent Document 1 discloses a laser powder additive manufacturing device that supplies resin powder onto a resin or metal substrate and irradiates the resin powder with a laser to manufacture a three-dimensional object made of multiple materials. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO2016 / 121013 publication Summary of the Invention [Problem to be solved by the invention]

[0004] The laser powder additive manufacturing device of Patent Document 1 supplies resin powder onto a metal substrate and irradiates the resin powder with a laser, so that the laser is irradiated to resin powder with a thermal expansion coefficient equal to or lower than that of the substrate. However, in one modeling layer, if a first material with a small thermal expansion coefficient and a second material with a large thermal expansion coefficient are arranged adjacent to each other and a first material region formed of the first material and a second material region formed of the second material are irradiated with a laser continuously, heat is transmitted from the region of the first material region and the second material region that is irradiated with the laser later to the region of the first material region and the second material region that is irradiated with the laser earlier and sintered or heated. For this reason, in the region adjacent to the first material region and the second material region, there is a risk that the modeling layer will be damaged by thermal stress caused by the laser, or the modeling layer will be deformed by heat caused by the laser, and there is a risk that the manufacturing accuracy of the three-dimensional object will decrease. [Means for solving the problem]

[0005] The three-dimensional modeling apparatus of the present invention for solving the above-mentioned problems is a three-dimensional modeling apparatus that manufactures a three-dimensional model by stacking modeling layers, and is equipped with a stage, a first material supply means for supplying a first material, a second material supply means for supplying a second material different from the first material, a laser irradiation means, and a control unit that controls the laser irradiation means by separating the first laser irradiation scan and the second laser irradiation scan, and is characterized in that when a first material region formed by supplying the first material from the first material supply means and a second material region formed by supplying the second material from the second material supply means are arranged adjacent to each other in one modeling layer, the control unit irradiates a laser from the laser irradiation means to the first material region in the first laser irradiation scan, and irradiates a laser from the laser irradiation means to the second material region in the second laser irradiation scan. [Brief description of the drawings]

[0006] [Figure 1] 1 is a schematic front view illustrating a configuration of a three-dimensional modeling apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic front view illustrating a configuration of a material supplying unit of the three-dimensional modeling apparatus of FIG. 1. [Diagram 3] FIG. 2 is a schematic perspective view showing a screw of the three-dimensional modeling apparatus of FIG. 1 . [Figure 4] 2 is a schematic plan view showing a state in which a modeling material is filled into the screw of the three-dimensional modeling apparatus of FIG. 1. [Diagram 5] FIG. 2 is a schematic plan view showing a barrel of the three-dimensional modeling apparatus of FIG. 1 . [Figure 6] 2 is a schematic front view illustrating a state in which a three-dimensional object is being manufactured using the three-dimensional printing apparatus of FIG. 1. [Figure 7] 2 is a flowchart of an example of a three-dimensional printing method using the three-dimensional printing apparatus of FIG. 1 . [Figure 8] 2 is a graph showing the energy intensity distribution of the laser used when irradiating a laser using the 3D modeling apparatus of FIG. 1. [Figure 9] 2 is a graph showing the heat distribution in the depth direction of the material of the laser used when irradiating the material with the laser using the 3D modeling apparatus of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] First, the present invention will be briefly described. A first aspect of the present invention for solving the above-mentioned problem is a three-dimensional modeling apparatus that manufactures a three-dimensional object by stacking modeling layers, and is equipped with a stage, a first material supply means for supplying a first material, a second material supply means for supplying a second material different from the first material, a laser irradiation means, and a control unit that controls the laser irradiation means by separating the first laser irradiation scan and the second laser irradiation scan, and is characterized in that when a first material region formed by supplying the first material from the first material supply means and a second material region formed by supplying the second material from the second material supply means are arranged adjacent to each other in one modeling layer, the control unit irradiates a laser from the laser irradiation means to the first material region in the first laser irradiation scan, and irradiates a laser from the laser irradiation means to the second material region in the second laser irradiation scan.

[0008] According to this embodiment, the laser irradiation means can be controlled by separating the first laser irradiation scan and the second laser irradiation scan. When the first material region and the second material region are adjacently arranged in one modeling layer, the first material region can be irradiated with the laser by the first laser irradiation scan, and the second material region can be irradiated with the laser by the second laser irradiation scan. Therefore, by irradiating the first material region and the second material region with the laser continuously, it is possible to suppress the heat from being continuously transmitted from the region irradiated with the laser later to the region irradiated with the laser earlier and sintered or heated to a high temperature. Therefore, it is possible to suppress the modeling layer from being damaged by thermal stress caused by the laser in the adjacent portion between the first material region and the second material region, and the modeling layer from being deformed by the heat caused by the laser.

[0009] A second aspect of the three-dimensional printing apparatus of the present invention is characterized in that, in the first aspect, the thermal expansion coefficient of the second material is greater than the thermal expansion coefficient of the first material, and the control unit controls the laser irradiation means to perform the second laser irradiation scanning of the second material region prior to the first laser irradiation scanning of the first material region.

[0010] When one modeling layer is formed using modeling materials with different thermal expansion coefficients, the modeling layer is easily damaged by thermal stress caused by the laser irradiation. In particular, when a region formed with a modeling material with a small thermal expansion coefficient is irradiated with a laser before a region formed with a modeling material with a large thermal expansion coefficient, the region formed with the modeling material with a small thermal expansion coefficient is easily damaged by the laser irradiation of the region formed with the modeling material with a large thermal expansion coefficient. However, according to this embodiment, even when one modeling layer is formed using a first material and a second material with different thermal expansion coefficients, it is possible to suppress damage to the modeling layer due to thermal stress caused by the laser.

[0011] The three-dimensional printing apparatus of a third aspect of the present invention is the three-dimensional printing apparatus of the second aspect, characterized in that the first material is ceramic.

[0012] According to this aspect, the first material is ceramic. Although ceramics are easily damaged by thermal stress after sintering, according to this aspect, even when ceramics is used as the first material, for example, it is possible to suppress further heat transmission from the second material region after the ceramic region is sintered, and it is possible to suppress damage to the ceramic region due to thermal stress caused by the laser.

[0013] A three-dimensional printing apparatus according to a fourth aspect of the present invention is the three-dimensional printing apparatus according to the second or third aspect, characterized in that the second material is a metal.

[0014] According to this embodiment, the second material is a metal. Metals easily transfer heat to adjacent regions, but according to this embodiment, even when a metal is used as the second material, for example, the second material region can be irradiated with a laser after the first material region has cooled, and damage to the first material region due to thermal stress caused by the laser can be suppressed. In particular, when a ceramic is used as the first material, damage to the ceramic region due to thermal stress caused by the laser can be effectively suppressed.

[0015] The three-dimensional modeling apparatus of a fifth aspect of the present invention is characterized in that in the first aspect, a sintering temperature of the second material is higher than a melting point of the first material.

[0016] When a second material having a sintering temperature higher than the melting point of the first material is used, the first material is likely to deform when the second material is irradiated with a laser. However, according to this embodiment, even when a second material having a sintering temperature higher than the melting point of the first material is used, for example, when the first material region is in a high temperature state, it is possible to suppress the transfer of heat from the second material region, and to suppress the deformation of the first material region due to the heat from the laser.

[0017] The three-dimensional printing apparatus of a sixth aspect of the present invention is the three-dimensional printing apparatus of the fifth aspect, characterized in that the first material is a resin.

[0018] According to this aspect, the first material is a resin. Generally, many resins are easily deformed by heat, but according to this aspect, even when a resin is used as the first material, for example, when the resin region is in a high temperature state, it is possible to suppress the heat from being transferred from the second material, and it is possible to suppress the deformation of the resin region due to the heat from the laser.

[0019] A three-dimensional printing apparatus according to a seventh aspect of the present invention is the three-dimensional printing apparatus according to the fifth or sixth aspect, characterized in that the second material is a metal or a ceramic.

[0020] According to this embodiment, the second material is a metal or ceramic. Although metal or ceramic easily transfers heat to adjacent regions, according to this embodiment, even when a metal or ceramic is used as the second material, for example, the second material region can be irradiated with a laser after the first material region has cooled, and deformation of the first material region due to heat from the laser can be suppressed.

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that all of the following drawings are schematic diagrams, and some components are omitted or simplified. In addition, the X-axis direction in each drawing is the horizontal direction, the Y-axis direction is the horizontal direction and also perpendicular to the X-axis direction, and the Z-axis direction is the vertical direction.

[0022] First, the overall configuration of a three-dimensional modeling apparatus 1 according to an embodiment of the present invention will be described with reference to FIGS.

[0023] The three-dimensional printing apparatus 1 of this embodiment is a three-dimensional printing apparatus that laminates printing layers 500 using a first material Oa and a second material Ob, and manufactures a three-dimensional object O by sintering both the first material Oa and the second material Ob with a laser L. As shown in Fig. 1, the three-dimensional printing apparatus 1 of this embodiment includes two material supplying means 30 that supply materials for forming the printing layers 500, a stage unit 22 as a stage for printing the three-dimensional object O, and a laser irradiation means 28 that can irradiate the printing layers with a laser L. Furthermore, the three-dimensional printing apparatus 1 includes a control unit 23 that controls the driving of each component of the three-dimensional printing apparatus 1, such as the material supplying means 30, the stage unit 22, and the laser irradiation means 28.

[0024] The three-dimensional modeling apparatus 1 of this embodiment includes, as the material supply means 30, a first material supply means 30A that supplies a first material Oa and a second material supply means 30B that supplies a second material Ob. A material different from the first material Oa is used as the second material Ob. For example, a material having a thermal expansion coefficient larger than that of the first material Oa is used. Also, for example, a material having a sintering temperature higher than the melting point of the first material Oa is used. In the three-dimensional modeling apparatus 1 of this embodiment, pellets 19 can be used as a modeling material for modeling the three-dimensional model O. That is, the first material supply means 30A uses a pellet 19A having the first material Oa, and the second material supply means 30B uses a pellet 19B having the second material Ob. The pellet 19A may contain other materials such as a binder in addition to the first material Oa, and the pellet 19B may contain other materials such as a binder in addition to the second material Ob. In the three-dimensional modeling apparatus 1 of this embodiment, the first material supplying means 30A and the second material supplying means 30B have exactly the same configuration.

[0025] 2 shows the material supplying means 30, but since the first material supplying means 30A and the second material supplying means 30B have exactly the same configuration, it corresponds to both the first material supplying means 30A and the second material supplying means 30B. As shown in Fig. 2, the material supplying means 30 includes a hopper 2 that stores pellets 19 as a molding material for forming a three-dimensional object O. The pellets 19 stored in the hopper 2 are supplied through a supply pipe 3 to a circumferential surface 4a of a screw 4, which is a substantially cylindrical flat screw.

[0026] The three-dimensional printing apparatus 1 of this embodiment is configured to use pellets 19 as a printing material for forming the three-dimensional object O, and to discharge the printing material while plasticizing it with a flat screw, but the present invention is not limited to the three-dimensional printing apparatus 1 configured as such. For example, the three-dimensional printing apparatus 1 may be configured to form the three-dimensional object O by continuously discharging from a discharge unit a filament that is a linear printing material made of resin, or a metal filament in which a metal powder is mixed with a resin material, while melting the filament. Furthermore, the three-dimensional object O may be formed by discharging from a discharge unit a fluid in which a first material Oa or a second material Ob is dissolved in a solvent or dispersed in a dispersion medium.

[0027] As shown in Fig. 3, a spiral groove 4b is formed on the groove forming surface 18, which is the bottom surface of the screw 4, from the circumferential surface 4a to the central part Cp. In other words, the ribs 4d formed as the grooves 4b are formed form the groove forming surface 18. In the three-dimensional modeling apparatus 1 of this embodiment, the drive motor 6 shown in Fig. 2 rotates the screw 4 about the Z-axis direction as the rotation axis, thereby supplying the pellets 19 from the circumferential surface 4a to the central part Cp while plasticizing them, as shown in Fig. 4. Although not shown in Fig. 1, cooling water circulates near the drive motor 6 to suppress a rise in temperature of the drive motor 6.

[0028] As shown in FIG. 2, the barrel 5 is provided at a position facing the grooved surface 18 of the screw 4 with a predetermined distance therebetween. A heating unit 7 is provided in the vicinity of the opposing surface 8 of the barrel 5, which is the upper surface of the barrel 5, facing the grooved surface 18. Since the screw 4 and the barrel 5 are configured as described above, the pellets 19 are supplied to the space portion 20 that corresponds to the position of the groove 4b and is formed between the grooved surface 18 of the screw 4 and the opposing surface 8 of the barrel 5 by rotating the screw 4, and the pellets 19 move from the circumferential surface 4a to the center portion Cp. When the pellets 19 move through the space portion 20 formed by the groove 4b, the pellets 19 are melted by the heat of the heating unit 7 and are pressurized by the pressure caused by moving through the narrow space portion 20. In this way, the pellets 19 are plasticized and supplied to the nozzle 10a through the communication hole 5a and discharged from the nozzle 10a.

[0029] As shown in FIG. 5 and other figures, a communication hole 5a, which is a movement path of the molten pellets 19, is formed in the center Cp of the barrel 5 in a plan view. As shown in FIG. 2, the communication hole 5a is connected to a nozzle 10a of a discharge unit 10 that discharges the modeling material. A filter (not shown) is provided in the communication hole 5a. Although not formed in the barrel 5 of this embodiment, a groove connected to the communication hole 5a may be formed in the opposing surface 8 of the barrel 5. By forming a groove connected to the communication hole 5a in the opposing surface 8, the modeling material may be more likely to gather toward the communication hole 5a.

[0030] Here, the discharge unit 10 is configured to be able to continuously discharge the plasticized modeling material in a fluid state from the nozzle 10a. As shown in FIG. 2, the discharge unit 10 is provided with a heater 9 for adjusting the modeling material to a desired viscosity. The modeling material discharged from the discharge unit 10 is discharged in a linear shape. Then, the modeling layer 500 is formed by discharging the modeling material in a linear shape from the discharge unit 10.

[0031] The three-dimensional modeling apparatus 1 of this embodiment includes a material supplying means 30 having a hopper 2, a supply pipe 3, a screw 4, a barrel 5, a drive motor 6, and a discharge unit 10. The three-dimensional modeling apparatus 1 of this embodiment includes one each of a first material supplying means 30A that discharges a first material Oa and a second material supplying means 30B that discharges a second material Ob, but may include a plurality of at least one of the first material supplying means 30A and the second material supplying means 30B.

[0032] As shown in FIG. 1, the three-dimensional modeling apparatus 1 of this embodiment includes a stage unit 22 for placing the modeling layer 500 formed by discharging from the material supply means 30. The stage unit 22 includes a base portion 221, a first table 222, a second table 223, and a third table 224. The first table 222 has a size in the Y-axis direction that extends from the modeling layer formation region 24 by the material supply means 30 to a laser irradiation region 25 by the laser irradiation means 28, the details of which will be described later. Under the control of the control unit 23, the second table 223 can be moved along the Y-axis direction relative to the first table 222 by a motor 225. Under the control of the control unit 23, the third table 224 can be moved along the X-axis direction relative to the second table 223 by a motor 226. Note that there is no particular limitation on the configuration of the stage unit 22. For example, a table and a motor for moving the second table 223 and the third table 224 from the modeling layer formation region 24 to the laser irradiation region 25 may be provided separately.

[0033] In the three-dimensional modeling apparatus 1 of this embodiment, the second table 223 moves along the Y-axis direction relative to the first table 222, thereby making it possible to move the second table 223 and the third table 224 from the modeling layer formation region 24 to the laser irradiation region 25. The second table 223 and the third table 224 are positioned in the modeling layer formation region 24, and the modeling layer 500 is formed by the material supply means 30, and the second table 223 and the third table 224 are positioned in the laser irradiation region 25, and the laser irradiation is performed by the laser irradiation means 28.

[0034] The material supplying means 30 is configured to be movable along the Z-axis direction by a motor (not shown) in the modeling layer forming region 24 as the modeling layers 500 are stacked, and the laser irradiating means 28 is also configured to be movable along the Z-axis direction by a motor (not shown) in the laser irradiation region 25 as the modeling layers 500 are stacked. The three-dimensional modeling apparatus 1 of this embodiment is configured in this way, so that the modeling layer 500 can be formed on the third table 224 while the stage unit 22 and the material supplying means 30 are moved relative to each other in the modeling layer forming region 24, and the laser L can be irradiated at a desired position on the modeling layer 500 formed on the third table 224 while the stage unit 22 and the laser irradiating means 28 are moved relative to each other in the laser irradiation region 25. The control of the arrangement of the stage unit 22 and the material supplying means 30 and the control of the arrangement of the stage unit 22 and the laser irradiating means 28 are both performed by the control unit 23.

[0035] As shown in FIG. 1, the laser irradiation means 28 includes a laser irradiation unit 281 and a galvanometer mirror 282. The laser irradiation means 28 radiates the laser L by oscillating the laser L of a predetermined output from the laser irradiation unit 281 based on a control signal from the control unit 23. The laser L is irradiated to the modeling layer 500, and sinters and solidifies, for example, metal powder contained in the modeling layer 500. At the same time, the binder contained in the modeling layer 500 is evaporated by the heat of the laser L. There is no particular limitation on the laser L, but a fiber laser is preferably used because of its advantage of high metal absorption efficiency. A YAG laser equipped with a Q switch and pulse-controlled may also be used.

[0036] Here, the first material Oa and the second material Ob are not particularly limited, but for example, the second material Ob may be a modeling material having a larger thermal expansion coefficient than the first material Oa. When one modeling layer 500 is formed using modeling materials having different thermal expansion coefficients, the modeling layer 500 is easily damaged by thermal stress caused by the laser L due to laser irradiation. In particular, when a region formed of a modeling material having a smaller thermal expansion coefficient is irradiated with a laser prior to a region formed of a modeling material having a larger thermal expansion coefficient, the region formed of the modeling material having a smaller thermal expansion coefficient is easily damaged due to the laser irradiation of the region formed of the modeling material having a larger thermal expansion coefficient. However, the three-dimensional modeling apparatus 1 of this embodiment controls the laser irradiation means 28 to perform the second laser irradiation scan on the second material region R2 prior to the first laser irradiation scan on the first material region R1 under the control of the control unit 23 described later. As a result, the three-dimensional printing apparatus 1 of this embodiment can prevent damage to the printing layer 500 due to thermal stress from the laser L, even when one layer of the printing layer 500 is formed using a first material Oa and a second material Ob having different thermal expansion coefficients.

[0037] Specifically, for example, ceramics can be preferably used as the first material Oa. Although ceramics are easily damaged by thermal stress after sintering, the three-dimensional printing apparatus 1 of this embodiment can suppress further heat transmission from the second material region R2 after the ceramic region as the first material region R1 is sintered, and can suppress damage to the ceramic region due to thermal stress caused by the laser L, even when ceramics is used as the first material Oa.

[0038] Moreover, a metal can be preferably used as the second material Ob. Although metals easily transfer heat to adjacent regions, the three-dimensional modeling apparatus 1 of this embodiment can, for example, irradiate the second material region R2 with a laser after the first material region R1 has cooled even when a metal is used as the second material Ob, and can prevent damage to the first material region R1 due to thermal stress caused by the laser L. In particular, when ceramic is used as the first material Oa, damage to the ceramic region due to thermal stress caused by the laser L can be effectively prevented.

[0039] Also, for example, the sintering temperature of the second material Ob can be higher than the melting point of the first material Oa. When the second material Ob having a sintering temperature higher than the melting point of the first material Oa is used, the first material Oa is easily deformed when the second material Ob is irradiated with a laser. However, the three-dimensional modeling apparatus 1 of this embodiment controls the laser irradiation means 28 to perform the first laser irradiation scanning on the first material region R1 and the second laser irradiation scanning on the second material region R2 separately under the control of the control unit 23 described later. In this way, even when the second material Ob having a sintering temperature higher than the melting point of the first material Oa is used, the three-dimensional modeling apparatus 1 of this embodiment can suppress the transmission of heat from the second material region R2 when the first material region R1 is in a high temperature state, for example, and suppress the deformation of the first material region R1 due to the heat from the laser L.

[0040] Specifically, for example, a resin can be preferably used as the first material Oa. Generally, many resins are easily deformed by heat, but even when a resin is used as the first material Oa, the three-dimensional printing apparatus 1 of this embodiment can suppress the transfer of heat from the second material Ob when the resin region as the first material region R1 is in a high temperature state, and can suppress the deformation of the resin region due to the heat from the laser L.

[0041] In addition, metal or ceramic can be preferably used as the second material Ob. Although metal or ceramic easily transfers heat to adjacent regions, the three-dimensional modeling apparatus 1 of this embodiment can, for example, irradiate the second material region R2 with a laser after the first material region R1 has cooled, even when a metal or ceramic is used as the second material Ob, and can prevent the first material region R1 from being deformed by the heat from the laser L.

[0042] However, as described above, the first material Oa and the second material Ob are not particularly limited, and various materials may be used in addition to metals, ceramic resins, etc. Also, two or more of these materials may be mixed and used.

[0043] Specifically, examples of metals or ceramics that can be used for the first material Oa and the second material Ob include various metals such as aluminum, titanium, iron, copper, magnesium, stainless steel, and maraging steel; various metal oxides such as silica, alumina, titanium oxide, zinc oxide, zircon oxide, tin oxide, magnesium oxide, and potassium titanate; various metal hydroxides such as magnesium hydroxide, aluminum hydroxide, and calcium hydroxide; various metal nitrides such as silicon nitride, titanium nitride, and aluminum nitride; various metal nitrides such as silicon carbide, titanium carbide, and aluminum nitride; various metal carbides such as silicon carbide and titanium carbide; various metal sulfides such as zinc sulfide; various metal carbonates such as calcium carbonate and magnesium carbonate; various metal sulfates such as calcium sulfate and magnesium sulfate; various metal silicates such as calcium silicate and magnesium silicate; various metal phosphates such as calcium phosphate; various metal borates such as aluminum borate and magnesium borate; and composite compounds thereof; and gypsum (hydrates of calcium sulfate and anhydrous calcium sulfate).

[0044] Examples of resins that can be used for the first material Oa and the second material Ob include, for example, acrylic resin, epoxy resin, silicone resin, cellulose-based resin, and synthetic resin. Examples of resins that can be used include thermoplastic resins such as PLA (polylactic acid), PA (polyamide), and PPS (polyphenylene sulfide). When using a resin as the second material Ob to be sintered by laser irradiation, a heat-resistant resin called a super engineering plastic such as PEEK (polyethyl ether ketone) can be preferably used. The resin may be in a pellet state containing the resin together with metal or ceramic. Instead of being in a pellet state, the metal, ceramic, or resin may be dissolved or dispersed in a solvent or dispersion medium in the form of fine particles. The solvent or dispersion medium or binder is usually dried and removed before irradiation with the laser L, or is decomposed and disappears with irradiation with the laser L.

[0045] Examples of the solvent or dispersion medium include various types of water such as distilled water, pure water, and RO water, as well as alcohols such as methanol, ethanol, 2-propanol, 1-butanol, 2-butanol, octanol, ethylene glycol, diethylene glycol, and glycerin, ethers (cellosolves) such as ethylene glycol monomethyl ether (methyl cellosolve), esters such as methyl acetate, ethyl acetate, butyl acetate, and ethyl formate, ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, and cyclohexanone, aliphatic hydrocarbons such as pentane, hexane, and octane, cyclic hydrocarbons such as cyclohexane and methylcyclohexane, benzene, and the like. Examples of the solvent include aromatic hydrocarbons having a long chain alkyl group and a benzene ring, such as toluene, xylene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dodecylbenzene, tridecylbenzene, and tetradecylbenzene; halogenated hydrocarbons, such as methylene chloride, chloroform, carbon tetrachloride, and 1,2-dichloroethane; aromatic heterocycles containing any one of pyridine, pyrazine, furan, pyrrole, thiophene, and methylpyrrolidone; nitriles, such as acetonitrile, propionitrile, and acrylonitrile; amides, such as N,N-dimethylamide and N,N-dimethylacetamide; carboxylates, and various other oils. The solvent or dispersion medium is usually removed by drying before irradiation with the laser L.

[0046] Next, an example of a three-dimensional printing method executed by the above-mentioned three-dimensional printing apparatus 1 will be described using the flowchart of Fig. 7 with reference to Figs. 6 and 8. The three-dimensional printing method of this embodiment is an example in which ceramic is used as the first material Oa and metal is used as the second material Ob. First, in step S110, the three-dimensional printing apparatus 1 inputs printing data from an external computer (not shown) or the like.

[0047] Next, in step S120, one modeling layer 500 is formed based on the modeling data input in step S110. Here, the top state diagram in Fig. 6 represents a state in which a second material region R2 as the first modeling layer 501 made of the second material Ob is formed on the third table 224 by the second material supply means 30B. The second state diagram from the top in Fig. 6 represents a state in which a first material region R1 as the first modeling layer 501 made of the first material Oa is formed adjacent to the second material region R2 on the third table 224 by the first material supply means 30A. 6 shows a state in which the first modeling layer 501 made of the first material Oa and the second material Ob is formed on the third table 224, but there are also cases in which the first modeling layer 501 made of only the first material Oa is formed on the third table 224, or the first modeling layer 501 made of only the second material Ob is formed on the third table 224. Also, in this embodiment, the second material region R2 is formed prior to the formation of the first material region R1, but the order of formation of these may be reversed.

[0048] Next, in step S130, the control unit 23 determines whether or not the second material region R2 exists in the one layer of the modeling layer 500 formed in step S120. If it is determined in step S130 that the second material region R2 exists, the process proceeds to step S140, where the second material region R2 is irradiated with the laser L by the second laser irradiation scan corresponding to the laser irradiation in one scan to sinter the second material region R2, and then proceeds to step S150. On the other hand, if it is determined in step S130 that the second material region R2 does not exist, the process proceeds to step S150 without proceeding to step S140. The third state diagram from the top in FIG. 6 represents a state in which it is determined that the second material region R2 exists in step S130, and the second material region R2 is irradiated with the laser L in step S140 to sinter the second material region R2.

[0049] In step S150, the control unit 23 determines whether or not the first material region R1 is present in the one layer of the modeling layer 500 formed in step S120. If it is determined in step S150 that the first material region R1 is present, the process proceeds to step S160, where the first material region R1 is irradiated with a laser L by a first laser irradiation scan corresponding to the laser irradiation in one scan to sinter the first material region R1, and then proceeds to step S170. On the other hand, if it is determined in step S150 that the first material region R1 is not present, the process proceeds to step S170 without proceeding to step S160. Note that the state diagram at the bottom of FIG. 6 represents a state in which it is determined that the first material region R1 is present in step S150, and the first material region R1 is irradiated with a laser L in step S160 to sinter the first material region R1.

[0050] In this embodiment, ceramic is used as the first material Oa, and metal is used as the second material Ob. Therefore, in order to prevent heat from the laser L from being transferred to the ceramic region by irradiating the adjacent metal region after sintering the ceramic, the second material region R2 is irradiated with the laser prior to the first material region R1. However, depending on the modeling material used, the first material region R1 may be irradiated with the laser prior to the second material region R2.

[0051] Here, the second laser irradiation in step S140 and the first laser irradiation in step S160 may be performed using a laser with the same waveform and the same pulse width, or may be performed using a laser with a different waveform or pulse width. For example, the second laser irradiation in step S140 may be performed in a laser irradiation mode that causes less heat diffusion to the surroundings than the first laser irradiation in step S160. Specifically, for example, the second laser irradiation in step S140 may use a laser with a shorter pulse width than the first laser irradiation in step S160. The diffusion of heat can be reduced by using a laser L with a shorter pulse width. This is because the shorter the pulse width, the more pinpoint energy can be concentrated.

[0052] Also, for example, a laser L having a top-hat shaped energy intensity distribution may be used in the second laser irradiation in step S140, and a laser L having a Gaussian distribution energy intensity distribution may be used in the first laser irradiation in step S160. Fig. 8 is a graph showing an example of the energy intensity distribution of a laser L having a top-hat shaped energy intensity distribution and a laser L having a Gaussian distribution energy intensity distribution.

[0053] Here, the laser L having a top-hat shaped energy intensity distribution is formed by incorporating a lens system (means for converting a Gaussian distribution to a top-hat shaped distribution) using a diffractive optical element (DOE) or the like capable of converting a laser profile to a top-hat distribution into the optical system of a laser light source having a Gaussian distribution generally adopted in the SLS (selective laser sintering) method or the SMS (selective mask sintering) method. However, there is no particular limitation on the lens system and it can be appropriately selected according to the purpose. For example, a device named StarLite manufactured by OPHIR can be used.

[0054] By using a laser L having a top-hat shaped energy intensity distribution, it is possible to uniformly apply thermal energy to a meltable region of a certain width, suppressing the supply of excessive thermal energy as in the Gaussian distribution, and suppressing the diffusion of heat over a wide range, compared to the case of using a laser L having a Gaussian distribution of energy intensity. As shown in the energy distribution shown in Fig. 8 and the graph of the heat distribution in the depth direction of the material shown in Fig. 9, by using a laser L having a top-hat shaped energy intensity distribution, it is possible to uniformly apply the amount of thermal energy required for melting to a meltable region of a certain width, suppressing the supply of excessive thermal energy as in the Gaussian distribution, and suppressing the diffusion of heat over a wide range.

[0055] As described above, after the end of step S160, the process proceeds to step S170. In step S170, the control unit 23 judges whether or not all three-dimensional modeling based on the modeling data input in step S110 has been completed. If it is judged that all three-dimensional modeling based on the modeling data input in step S110 has been completed, the three-dimensional modeling method of this embodiment is terminated. On the other hand, if it is judged that all three-dimensional modeling based on the modeling data input in step S110 has not been completed, the process returns to step S120, and steps S120 to S170 are repeated for all of the desired modeling layers 500, in the order of the first modeling layer 501, the second modeling layer 502, ..., until it is judged that all three-dimensional modeling based on the modeling data input in step S110 has been completed. Here, when the ceramic regions of the upper layer and the lower layer are in contact with each other and the metal region of the upper layer is irradiated with a laser, the heat irradiated to the metal region improves the adhesion of the laminated interface of the ceramic regions of the upper layer and the lower layer.

[0056] In this way, when a first material region R1 formed by supplying the first material Oa from the first material supply means 30A and a second material region R2 formed by supplying the second material Ob from the second material supply means 30B are adjacent to each other in one modeling layer 500, the control unit 23 separates the scanning of the laser irradiation between the first material region R1 and the second material region R2. In other words, the control unit 23 causes the laser irradiation means 28 to irradiate the first material region R1 with the laser L in the first laser irradiation scanning corresponding to step S160, and causes the laser irradiation means 28 to irradiate the second material region R2 with the laser L in the second laser irradiation scanning corresponding to step S140.

[0057] In this way, the three-dimensional modeling apparatus 1 of this embodiment controls the laser irradiation means 28 by separating the first laser irradiation scan from the second laser irradiation scan, which performs laser irradiation so as not to be continuous with the first laser irradiation scan. In the three-dimensional modeling apparatus 1 of this embodiment, when the first material region R1 and the second material region R2 are arranged adjacent to each other in one modeling layer 500, the first material region R1 is irradiated with the laser L by the first laser irradiation scan, and the second material region R2 is irradiated with the laser L by the second laser irradiation scan. For this reason, by performing three-dimensional modeling using the three-dimensional modeling apparatus 1 of this embodiment, the first material region R1 and the second material region R2 are irradiated with the laser L in succession, and it is possible to suppress the heat from being continuously transmitted from the region irradiated with the laser L to the region irradiated with the laser L earlier and sintered or heated to a high temperature. Therefore, the three-dimensional printing apparatus 1 of this embodiment can prevent the modeling layer 500 from being damaged by thermal stress caused by the laser L, and from being deformed by the heat from the laser L, for example, in the adjacent portion between the first material region R1 and the second material region R2. Note that "thermal stress" refers to a sudden change in temperature, and corresponds to a case where a sudden change in volume is caused by a sudden change in temperature.

[0058] The present invention is not limited to the above-mentioned embodiments, and can be realized in various configurations without departing from the spirit of the present invention. The technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention can be appropriately replaced or combined in order to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0059] Reference Signs List 1...three-dimensional modeling device, 2...hopper, 3...supply pipe, 4...screw, 4a...circumferential surface, 4b...groove, 4d...rib, 5...barrel, 5a...communicating hole, 6...driving motor, 7...heating section, 8...opposing surface, 9...heater, 10...discharge section, 10a...nozzle, 18...groove forming surface, 19...pellets, 19A...pellets, 19B...pellets, 22...stage unit (stage), 23...control section, 24...modeling layer forming area, 25...laser irradiation area, 28...laser irradiation means, 3 0...material supply means, 30A...first material supply means, 30B...second material supply means, 221...base portion, 222...first table, 223...second table, 224...third table, 225...motor, 226...motor, 281...laser irradiation portion, 282...galvanometer mirror, 500...modeling layer, 501...first modeling layer, 502...second modeling layer, Cp...center portion, O...three-dimensional object, Oa...first material, Ob...second material, R1...first material region, R2...second material region

Claims

1. A three-dimensional modeling apparatus for manufacturing a three-dimensional object by stacking modeling layers, comprising: Stage and A first material supplying means for supplying a first material; a second material supplying means for supplying a second material different from the first material; A laser irradiation means; a control unit that controls the laser irradiation means by separately performing a first laser irradiation scan and a second laser irradiation scan; Equipped with The control unit controls a first material region formed by supplying the first material from the first material supply means, and a second material region formed by supplying the second material from the second material supply means; are arranged adjacent to each other in one layer of the modeling layer, a laser is irradiated from the laser irradiation means to the first material region by the first laser irradiation scanning, and a laser is irradiated from the laser irradiation means to the second material region by the second laser irradiation scanning, The thermal expansion coefficient of the second material is greater than the thermal expansion coefficient of the first material; The control unit controls the laser irradiation means to perform the second laser irradiation scanning on the second material region prior to the first laser irradiation scanning on the first material region.

2. The three-dimensional modeling apparatus according to claim 1 , The three-dimensional modeling apparatus, wherein the first material is a ceramic.

3. 3. The three-dimensional modeling apparatus according to claim 1, The three-dimensional modeling apparatus, wherein the second material is a metal.

4. The three-dimensional modeling apparatus according to claim 1 , A three-dimensional modeling apparatus, wherein a sintering temperature of the second material is higher than a melting point of the first material.

5. The three-dimensional modeling apparatus according to claim 4, The three-dimensional modeling apparatus, wherein the first material is a resin.

6. The three-dimensional modeling apparatus according to claim 4, The three-dimensional modeling apparatus is characterized in that the second material is a metal or a ceramic.

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